Air control mechanism and switch for oil burners



8- 1948' D. KAUFMAN 2,446,834

AIR CONTROL MECHANISM AND SWITCH FOR OIL BURNERS Filed Aug. 21, 1943 INVENTOR I;1UFMAA A NEY Patented Aug. 10, 19 48 UNITED STATES P TENT OFFICE 2,440,834 7 Araqou'raor, amonmsmnim swrrcn won on. nuaucas Daniel Kaufman, New Haven, Conn., mignor, by

meone assignments, to The Oil Equipment Manufacturing Corporation, New Haven, Conn., a corporation of Connecticut 2 Claims.

This invention relates to new and useful immovements in air control mechanism, particularly as applied to gun type oil burners.

A principal object of the invention is to provide' a mechanism of this character wherein the heat in the combustion chamber will be conserved, the volume of air admitted to the combustion chamber easily and effectively controlled, and the parts arranged so that the oil burner will not function until the air ports are opened. This latter sequence of operations eliminates the hazard of an explosion with its destructive results. A further object is to provide a device that will be relatively simple in its operation, constructed at the minimum cost and adapted to be assembled either before or after the oil burner mechanism is installed. Other and further objects of the invention will become apparent from the following description of a preferred form of the'invention in connection with the accompanying drawings, wherein like numerals of reference indicate like parts in the Figure 3 is a fragmentary view, the parts in section being taken generally upon line 1-3 of Figure 2;

Figure 4 is an-enlarged cross sectional view of the fluid cylinder and associated parts, the parts in section being taken generally upon line 4-4 of Figure 2;

Figure 5 is a diagrammatic view of the electric wiring; and 1 Figure 6 is an enlarged view of the piston head and flap valve..

- Referring to the drawings, the numeral I indicates a fan housing of a gun type oil burner, through one end of which is an opening 48; I is a portion of an electric motor mounted therein; and 1 a fan fixed on the motor armature. Adjacent to the fan housing I is a combustion chamber (not shown), into which air is driven by the fan I from the Ian housing I. Alongside the fan housing I is a valve housing 8, shown herein as being substantially rectangular in form, with a bottom portion I, through which is an opening or port II and surrounding wall portions l4. Fixed to the valve housing I at one end is an electric magnet l2 and to the opposite end a fluid cylinder l3. This latter is closed at one end and provided with a head [4 at the other end, through which passes a piston rod II, having a piston II thereon within the cylinder l3. Through the piston is a port I1 and on one side thereof is a fiap valve II, which operates in a conventional manner. Through this fiap valve, and in register with the ports ii are the ports 43 of less'area than the ports ii. The cylinder II is filled with a fluid, preferably oil, and as the piston l I moves toward the magnet, the oil from the upper end of the cylinder flows through the ports l1 and by the'flap valve II, which opens outwardly, and into the lower end of the cylinder. When the piston moves in the reverse direction the fluid passes through the ports 41 and ports i1 to the upper end of the cylinder. As the area of the ports 42 is less than the ports ii, the piston will move toward the magnet at an accelerated speed relative to its movement in the opposite direction.

Within the valve housing 8. and slidable alongside the bottom thereof under the caps 41, is a plate It having one or more rectangular ports 20 therethrough, a lip 2| at its lower end, and an offset lug 22 at its upper end. Projectin through an end wall Ill of the valve housing and the oflset lug 22 is an adjusting screw 23 having a nut 24 thereon. Endwise movement of this screw is prevented by a collar 25 fixed thereon. By manipulation of the screw 23 the plate i9 is moved toward and away from the magnet l2, thereby adjusting its relative position within the valve housing I. Movable on this plate l9, and held in engagement therewith by the lugs 26, is a slide 21, having one or more rectangular ports 28 therethrough, corresponding in number with the ports 20 and of substantially the same size and shape. In'one position of the slide relative to the plate I9,-the ports 20 and 28 are in l'egiste'r with each other and fully open. On the slide 21 is an armature block 29, positioned opposite the magnet 30 of the electric magnet H. The

' piston rod II projects through a lug 3| on the nected to the magnet by a wire, the contact point 38 with a house or other convenient circuit by a wire 44, and with the fixed contact plate 33 by the wire 40. The contact plate 34 is connected with one brush 4| of the motor 6 by the wire 45 and the other brush by a wire 42 to the house cir- 'cuit.

As shown in the drawings, the air inlet ports through the slide 21 and the plate It are closed ment.

walls thereof as well as the furnace or boiler fiues and cooling the entire heating plant. The system begins to function when the arm 37 of the thermostat at a predetermined temperature engages the contact point 38 and closes the electric circuit. The current then energizes the magnet I 2. Before being energized, the armature 30 of the magnet 12 is in substantially the position shown in the drawings, that is, in engagement with the armature block 29 on the slide 27. When the magnet is energized the armature 30 is drawn into the body thereof and pulls with it the slide 21. During this action the piston I6, through the piston rod I5, is moved upwardly in the cylinder l3, the fluid therein passing through the port 17 from above to below the piston. This movement of the slide 27 uncovers the air inlet ports 20 through the plate l9 and when near the upward limit of its movement the contact arm'35 upon the slide 27 engages the contact plate 34 and forces it against the fixed contact plate 33, closing the circuit to the motor 6. Rotation of the motor starts both the fan I and the oil pump (not shown), which then function in a well known and conventional manner.

The fan draws air into the housing through the ports 28 and 20 and forces it into the combustion chamber where the oil supplied by the pump is atomized and unites with the air, providing a proper mixture for combustion'purposes.

If and when the temperature is raised, action of the thermostat as a result thereof moves the arm 31 away from the contact point 38 upon the elec tric circuit. Engagement of the contact arm with the contact plate 34 is thus broken and the current to the motor 6 is shut ofi, thus stopping the oil pump and shutting off the oil supply and also rotation of the fan I.

The drop speed of the slide 27 is determined by the speed of travel of the fluid in the cylinder l3 under the piston to the top thereof through the ports 43 and [1. As the port 43 is smaller in area than the port I! the speed of the down movement of the slide 21 is much slower than its up speed. When the temperature returns to the predetermined degree the sequence of operations hereinbefore described are repeated.

Due to the fact that the slide 27 moves downwardly at a relatively slow speed the air ports close slowly, thus permitting sumcient air to pass through the ports 28 and 20 to drive out any products of combustion that may remain in the com.-

bustion chamber. The combustion chamber is thus clear of gases, atomized fuel and. products of combustion, resulting from the last prior operation of the burner. The volume of air admitted to the combustion chamber decreases as the slide 27 moves downwardly until the ports are entirely closed at which time the clearing operation of the air within the combustion chamber has completed its work and no more air is admitted.

Heretofore in the conventional type of mechanism of this character, some gases, atomized fuel and products of combustion have remained within the combustion chamber after the burner has ceased to function, with the result, that upon occasion, at the next starting of, the burner, there is a premature explosion with disastrous results to both the burner and adjacent mechanism.

When the rectangular ports are fully closed, the lower edge of the slide 27 rests upon the lip 2| on the plate 19, thus limiting its downward move- The required volume of air passing through the ports to provide a proper mixture of vaporized oil and air may be varied. This is accomplished by adjusting the position of the plate l9 toward and away from themagnet l2 through manipulation of the screw 23 therewith. As the plate 21 rests upon the lip 2i the armature 30 is pushed into the magnet body H as the plate l9 moves toward the magnet. There is thus less travel for the slide 21 before the arm 35 engages the contact plate 34.

The ports 20 and 28 are shown herein as rectangular, but they may be of other shapes if desired.

Some parts of this mechanism are insulated from other parts. In such instances, any approved form of insulation may be used.

Minor changes and alterations, within the spirit and scope of the appended claims, may be made in the preferred embodiment of the invention illustrated herein.

What is claimed is:

1. In a mechanism of this character described, air control means comprising a housing member having an inlet port ther'ethrough, a plate having ports therethrough and adjustable relatively to the inlet port of the housing, a vertically movable slide having ports therethrough movably mounted on the plate to cause the ports to cover and un cover the ports through said plate on movement of the slide relatively to the plate, means to stop the downward movement of the slide, said slide 2. A mechanism as in claim 1,' including an electric switch mounted on the housing adjacent the slide, and means upon said slide to engage and actuate said switch.

' DANIEL KAUFMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 741,474 Ferry Oct. 31, 1903 957,776 Ilg May 10, 1910 1,192,141 White July 25, 1916 1,448,409 Kindl Mar. 13, 1923 1,544,730 Dressler July 7, 1925 1,633,498 Seelbach June 21, 1927 1,787,653 Anderson Jan. 6, 1931 1,917,340 Sutcliffe July 11, 1933 1,955,797 Engstrom Apr. 24, 1934 1,980,789 Dillman he Nov. 13, 1934 2,067,426 Stuart Jan. 12, 1937 2,117,787 Bock May 17, 1938 2,122,050 Stuart June 28, 1938 2,259,973 Firehammer Oct. 21, 1941 FOREIGN PATENTS Number Country Date 460,182 Great Britain Jan. 19, 1937 

